"The extent of crime (or what was considered crime) in London may be gauged by the number of prisons: ten. Newgate is pictured here; another well-known one was the Clink, immortalized in English slang.

A Warden at the time would still have had to purchase his right to run the prison he was responsible for. And he would then be expected to make a profit by charging the inmates for their "room and board". Paupers were nevertheless entitled to a (very) bare minimum - which would be paid for indirectly by the better off prisoners.

Very much like the way tax farmers worked - and many similar public offices.